Study of the Interaction of Rubidium Atoms with Sapphire Surface Using Spectroscopic Nanocells

Abstract

The influence of the dielectric surface on Rb atoms of D₂-line at nanometer distances has been experimentally studied. The use of a nanocell filled with atomic rubidium with a wedge-shaped gap, has made it possible to study the influence of the distance of atoms in the range of 45–150 nm from the surface of a window made of commercial sapphire. At distances from the sapphire surface of less than 130 nm, due to the van der Waals interaction, ⁸⁵Rb and ⁸⁷Rb atomic transitions are strongly broadened, and their frequency shifts are carried out to the low-frequency spectrum region. The use of the method of the second derivative of the nanocell absorption spectra has made it possible to measure the van der Waals interaction coefficient C₃ = 1.8±0.3 kHz ∙ μm³ for Rb D₂-line. It is shown that at a nanocell thickness of 65±5 nm, an additional red shift occurs with atoms density increase, due to the dipole-dipole interaction of Rb atoms. The results can be used in the development of miniature submicron devices.